In a prior art method of making an integrally foam-molded seat, a seat surface cover is placed inside a mold to extend along the internal contour of the molding cavity of the mold, and a polyurethane resin solution is directly injected onto the surface cover in the mold to make the desired integrally foam-molded seat. In this molding process, embossed patterns or relief patterns (such as those for grooves, button-like formations, and emblems or other designs) are formed on the surface cover. However, the prior art method has the following defects:
(A) It is difficult to accurately position marginal end edges of the surface cover at the predetermined portion of the mold. Experience and man-hours are required therefor, and rejects are apt to be produced.
(B) Because the foaming pressure only is resorted to for molding the polyurethane foam integrally combined with the surface cover, the molded shape is not accurate due to the insufficient pressure.